I can't imagine how long it must have taken to create a fully-voiced cutscne with so many different shots and unique assets! What an intro!
I am very impressed that you wrote logic for a CPU-controlled second player. It fell right in line with the jam theme, and made the race feel much more urgent when you could see your rival racking up points to your immediate right.
It was interesting that you could use the rocks to slow your descent. I felt like I was constantly weighing the benefit of moving downward faster vs. slowing myself so it was easier to grab gems.